Genesis 7:2-3, 8-9

Of every clean beast thou shalt take to thee seven and seven, the male and his female; and of the beasts that are not clean two, the male and his female: of the birds also of the heavens, seven and seven, male and female, to keep seed alive upon the face of all the earth.

Of clean beasts, and of beasts that are not clean, and of birds, and of everything that creepeth upon the ground, there went in two and two unto Noah into the ark, male and female, as God commanded Noah.